


The Moon Theory

by dasfreefree, imagine_that_haikyuu



Category: Haikyuu!!
Genre: F/M, Female!Reader - Freeform, Fluff and Humor, Menstruation mention, Reader-Insert, references to Sailor Moon
Language: English
Status: Completed
Published: 2020-06-10
Updated: 2020-06-10
Packaged: 2021-03-04 06:35:30
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,083
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24649588
Author URL: https://archiveofourown.org/users/dasfreefree/pseuds/dasfreefree, https://archiveofourown.org/users/imagine_that_haikyuu/pseuds/imagine_that_haikyuu
Summary: Oikawa has an interesting theory about your nasty headaches.
Relationships: Oikawa Tooru/Reader
Kudos: 88





	The Moon Theory

**Author's Note:**

> This scenario was originally posted on January 24, 2017 to our [tumblr](https://imagine-that-haikyuu.tumblr.com/post/156323698990/i-hope-this-isnt-too-weird-but-could-i-get-a). Some edits have been made since then.
> 
> Writer: Rachel Lauren
> 
> Anonymous asked: I hope this isn't too weird but could I get a scenario where Oikawa notices his girlfriend keeps getting headaches anytime theres a full moon or the moon is closer to the earth than usual and has convinced himself that she's an alien and her kind are trying to locate her and take her back home and now he must protect her? I notice this happens to me sometimes(minus a cute boyfriend worried that I'm an alien)!

“I knew it!”

Oikawa has his face plastered to your window, eyes staring up into the night sky. Normally, you’d be enthusiastic over his discovery too, but you had no idea what he was proud about this time. That and he was being a little loud; it wasn’t terrible, but given the current pounding in your head, you couldn’t tolerate much above soft voices.

“Sweetie, please keep it down. My head’s killing me,” you plead, bringing two fingers from each hand to your temples to massage them. The ibuprofen should have kicked in already, but it was clear that it wasn’t doing much to lessen the pain.

He removes his face from the glass to peer at your lying form on the bed. There’s a pleased look on his face, as if he just figured out who the culprit was in mystery novel before the main character did.

“Sorry,” he admits with a lower tone. “But it’s just as I thought.”

You don’t say anything, but your confused expression is enough for him to continue.

“There’s a full moon out tonight.”

You sigh, “That again? Tooru, did you stay up watching _The X-Files_ again?”

You always knew Oikawa could be silly, and certainly this was one of his quirks that you enjoyed the most. As of late, you noticed around the same time every month, you’d get some awful headaches. Your boyfriend happened to realize that this occurrence also coincided with the moon’s cycle, specifically that you’d get them when there was a full moon. This—combined with him binge-watching his favorite sci-fi series on nights he couldn’t sleep—led him to theorizing something so completely ridiculous that you wondered if he was really serious about it.

The theory: that you were in actuality an _alien princess_ —heavy emphasis on princess—who was kidnapped by an Earthling as baby, only to wind up at the door current Earth family who of course took you in. Your true family is using the moon as a homing beacon to find you. The headaches that you get? Your brain reacting to the signal. However, this homing beacon is solar powered and so you only feel its effects during a full moon when it’s at full power. And because that time is limited, it’s taking your family a long time to find you.

The first time he explained it to you, you laughed heartily and kissed him on the cheek as thanks for trying to make you feel better. Laughter is the best medicine after all. It’s been months now, though, and Oikawa is still insisting that this is what’s happening. You honestly still can’t tell if he’s just pulling your leg or if he’s even capable of pulling off such a lengthy joke. Maybe you do have to scar him with the video of your birth if he doesn’t stop soon.

“Well, it only makes sense. Do you have any other possible explanation, (F/N)?” He rises from your desk chair to sit on the edge of your bed.

“It could just be that I’m getting my period soon? It usually comes a day or so after this happens,” you muse.

He hums with a little disappointment. “I’m sure that’s what your kidnappers want you to think.”

Despite the smile on your lips, you sigh. The pain’s subsided to a degree, but you knew it would only be a matter of minutes before you would be completely miserable again. Oikawa reaches a hand out to your head, and strokes your hair gently.

“Let me spoil you, my princess,” he says. He wiggles his fingers on his other hand “I’ll put these majestic setter hands to work to make that nasty headache disappear.”

You rise slowly and giggle, “What a treat. Some TLC from the Grand King himself!” You plant a soft kiss on his lips before shifting yourself on the bed with your back to him. The mattress sinks as he positions himself behind you properly. “But wouldn’t it make it harder for my supposed ‘real family’ to find me then?”

You can practically hear Oikawa pouting, but his fingers still rake their way into your hair to massage your scalp. Even if it doesn’t do much to alleviate your headache, the tender stroking against your head still feels wonderful.

“Well, I can’t just have you taken away from me like that even if they are your _real_ family. It wouldn’t be like me to not protect what I love.”

Those words could make you swoon if they weren’t so wrapped up in his wacky theory. Still, you find yourself grinning widely, wanting to turn around and kiss him again. Instead, you let out another sigh, dreamily this time.

“Besides, it only seems befitting that I, a king from Earth, and you, a beautiful space princess, would find themselves in love with one another.”

Maybe he had been reading or watching too many fantasies or European fairy tales instead of indulging in sci-fi like you thought. You almost speak to voice your agreement and tell him how sweet he’s being, but stop when you open your mouth. Something about what he just said seems a little _too_ familiar.

“Tooru…” you coo, “isn’t…isn’t that what happens in _Sailor Moon_?”

Oikawa’s fingers stop working your scalp, but start again after a brief hesitation. “Is that true?”

There’s a slight crack in his voice, not unlike the other times you caught him fibbing about minutia. You snort and place your hands on his before gingerly lifting them off your head. Before you even turn around to face him, you can already tell he’s crossed his arms over his chest and looking off elsewhere in the room with his nose in the air. The only thing missing is a pout, but he’s trying to come of a little less childish right now. Not that it’s working because now you’re laughing wholeheartedly anyway. You peck him on the cheek and Oikawa’s eyes snap their focus back to you.

“My head feels much better now,” you say. “Thanks to your royal treatment and that good laugh.” He groans, but you ignore it to kiss him again, this time on the lips. His arms uncross and he places his hands on your waist to pull you closer.

It’s just as you figured because this king is very weak to his beloved princess’s kiss. And outlandish alien theories aside, he’d do anything to make sure that he could kiss you again and again.


End file.
